1. Field of the Invention
The present invention relates to a drum type washing machine, and more particularly, to a structure of a driving unit in a drum type washing machine.
2. Background of the Invention
In general, a drum type washing, making washing by using friction between a drum rotated by a motor and laundry in a state detergent, washing water, and the laundry are introduced into the drum, provides effects of beating and rubbing washing, but gives almost no damage to the laundry, and shows no entangling of the laundry. A structure of a related art drum washing machine will be explained with reference to FIG. 1. FIG. 1 illustrates a longitudinal section of a related art drum type washing machine, provided with a tub 2 mounted inside of a cabinet 1, a drum 3 rotatably mounted on a central portion of inside of the tub 2. There is a motor 5a under the tub 2 connected with a pulley 18. There is a drum shaft 25 connected to a rear of the drum 3, to which a drum pulley 19 is coupled. And, the drum pulley 19 on the drum shaft and the motor pulley 18 connected to the motor 5a are connected by a belt 20 for transmission of power. And, there is a door 21 in a front part of the cabinet 1, with a gasket 22 between the door 21 and the tub 2. There is a hanging spring 23 between an inside of an upper portion of the cabinet 1 and an outside of an upper portion of the tub 2, and a friction damper 24 between an inside of a lower portion of the cabinet 1 and a lower side of an outside of the tub 2 for damping vibration of the tub 2 generated during spinning. There is a detergent container 26 in the upper front of the cabinet 1, and in the upper back of the cabinet 1 is a water supply valve 27 for supplying water to the detergent container.
However, the related art washing machine has the following disadvantages since driving power of the motor 5a is transmitted to the drum 3 through the motor pulley 18, and the drum pulley 19, and the belt 20 connecting the motor pulley 18 and the drum pulley 19.
First, there is a loss of energy in a course of driving power transmission because the driving power is transmitted from the motor 5a to the drum 3, not directly, but through the belt 20 wound around the motor pulley 18 and the drum pulley 19.
And, the driving power transmission from the motor 5a to the drum 3, not directly, but through many components, such as the belt 20, the motor pulley 18, and the drum pulley 19, causes much noise in the course of power transmission.
The lots of components required for transmission of driving power from the motor 5a to the drum 3, such as the motor pulley 18, the drum pulley 19 and the belt 20, require many assembly man-hours. And, the more the number of components required for transmission of driving power from the motor 5a to the drum 3, the more number of spots which require repair, and the more frequent at which repair required. The imbalance caused by the motor mounted to a lower part of rear of the tub 2 causes heavy vibration when the motor is rotated. Consequently, there is a weight balancer of metal or cement separately provided to an opposite position of the motor for system balancing.
In summary, the indirect driving power transmission from the motor 5a to the drum 3 through the motor pulley, the drum pulley, and the belt requires many repair, has much noise, waste of energy, and results in a deterioration of a washing capability.
Accordingly, the present invention is directed to a structure of a driving unit in a drum type washing machine that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a structure of driving unit in a drum type washing machine, in which the motor is coupled to the drum directly for reducing vibration, and either reducing a weight of the weight balancer or remove the weight balancer completely.
Another object of the present invention is to provide a structure of driving unit in a drum type washing machine, which can reduce waste of energy by employing a BLDC motor that has a good energy efficiency.
Other object of the present invention is to provide a structure of driving unit in a drum type washing machine, which involves no deformation of the rotor even if the rotor rotates at a high speed.
Further object of the present invention is to provide a structure of driving unit in a drum type washing machine, which permits an easy assembly of the drum washing machine.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purposes of the present invention, as embodied and broadly described, the structure of a driving unit in a drum type washing machine includes a tub for storing washing water, a drum rotatably mounted inside of the tub disposed horizontal to the ground, or with an angle to the ground for accommodating laundry therein, a shaft connected, through the tub, to the drum mounted inside of the tub, for transmission of a driving force of the motor to the drum, bearing fitted each onto an outer circumference of the shaft for supporting the shaft, a bearing housing having stator fastening bosses disposed at fixed intervals along a circumference of a central portion thereof, for supporting the bearings, a stator having a plurality of magnetic cores formed by stacking magnetic laminations, each having a salient pole projected outward and a plurality of coils each wound around a respective one of the salient poles, and a cup formed rotor having a rotor body and permanent magnets, the rotor by comprising a sidewall and a rear wall to cover an outer circumference and a bottom of the stator, the permanent magnets fitted to the side wall, ad a connecter connecting the rotor and the shaft.
Preferably, the salient poles of the stator are projected outward in a radial direction with respect to a central longitudinal axis of the stator. Preferably, the stator further comprises a frame of insulating material for covering top and bottom surfaces of a magnetic core assembly of the magnetic cores. And preferably the stator further comprises a plurality of fastening ribs projected inward, each with a fastening hole for fixing the stator to the bearing housing. More preferably the fastening ribs are projected inward in the radial direction. And more preferably the fastening ribs are formed as one unit with the frame.
Preferably the rotor body is formed of magnetic material such as iron or iron alloy, which enables the side wall of the rotor body to serve as a back yoke that forms a magnetic flux path. Preferably the rear wall of the rotor body is formed as one unit with the sidewall. Preferably the permanent magnets are fitted to a setting surface of an xe2x80x9cLxe2x80x9d formed bent portion of the side wall.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.